The present invention relates to artificial knee joint components containing index marks to indicate the position of one component with respect to the other.
During knee joint replacement surgery it is desirable to know where the contact point between the femoral and tibial components lies relative to the anterior-posterior dimension of the tibia. This information can aid in aligning the components for proper location of the initial contact between the femoral and tibial components. It is also informative to know how the location of this contact point changes during flexion and extension of the knee joint. If the contact point shifts posteriorly several millimeters, known as rollback, and the posterior cruciate ligament (PCL) is intact, the PCL is causing at least some of the rollback and therefore is functional. A surgeon can then make informed decisions as to the appropriate type of implant, the balancing of soft tissue tension around the knee joint by carefully severing certain tissues, and the adjustment of component alignment. With prior knee joint components, both the implants themselves and the provisional implants used for size selection, there is no indicator to aid in quantifying contact point location or contact point change in location.